This project will continue its investigation of islet transplantation in mice with virus-induced diabetes mellitus and will continue the search for secondary renal lesions in mice with viral diabetes. Encephalomyocarditis virus (EMCV) produces diabetes mellitus when administered intraperitoneally to mice. During the first year of this project we showed that the diabetes mellitus these mice had could be reversed by transplantation of the islets of Langerhans and that the transplanted islets did not succumb to EMCV infection. Furthermore, islets transplanted to the spleens of mice with chemical diabetes were not susceptible to challenge with EMCV. This viral susceptibility depending on islet location will be further investigated during the second year of this project. Mice with EMCV-induced diabetes develop deposition of IgA, IgG, and IgM on their renal glomeruli. Light microscopy shows mesangial cell proliferation. These changes occur during the first month posttransplant. During the second year of this project mice will be followed longer to determine whether they develop secondary lesions more similar to the Kimmelstiel-Wilson disease found in human diabetes mellitus.